Rafter gauge



May i0 1927. 1,628,447

E. ATTAWAY RAFTER GAUGE Filed April 17. 1925 15 the main rafter.

Patented Mayf10, '11927. l* l' amsn ATTAwaY, oir` Louausroacr, Louisiana.

. i narran euren.v

lAppliance mea apra 17, 1923. gseriai no. e2,7e2.'

' present invention pertains to scale finding instruments, and-it'contemplates the provlslon of a simple and inexpensivel instrument through the medium of which thev '.5 Ieriii of main and hip rafters may be ly; and easily ascertained in proportion v ment las assembled, but I would distinctly re to eac other.

I might state at this `point that inmeasuring roofs for which my device is adapted,

the irst hypotenuse isKconsidered thel vmain rafter of a roof because it is readily apparent or rst to be obtained while the second hypotenuse is the hip vrafter because it is determined by measurements taken from The invention further contemplates the provision of an `instrument so constructed and arranged that the angles of roofs may be laid out in a very simple manner by any person even though theyv be. unskilled in the art to which the instrument pertains.

The invention in all of its details` will be fully understood from the following description and claim, when the same are read .in 26 connection with the drawings accompanying and forming part of this specification, in which:

Figure 1 isa perspective view of the instrument comprising my invention.

Figure. 2 is a top p an view of the protractor plate of the device- Figure 3 is a sectional view taken in the plate indicated by the line 3 3 of Figure 1 showing the arms in closed posltlon and looking in the direction of the arrow.

Figure 4 is an enlarged sectional view taken in the plane indicated by the line 4--4 of Figure 1, and looking in the dlrection of the arrow.

Similar numerals of reference designate corresponding parts in all of the views of the drawings. v

My novel instrument comprlses the rule or arm 1, that is preferably, though not necessarily rectangular in cross-section, and said rule 1 is provided with a right angle portion 3 that rests u on and is secured to the base plate or ortion 2, that in turn is superimposed ont e protractor plate 4 that is marked o in degrees -and as will be clearly manifest by reference to Figure 1 the plate 4 as well as portion 3 are a apted to receive a screw 5, for an important purpose hereinafter set forth.

Adapted to be swung on the pivotL of the festly sc rew- 5 is a .rule 6 that is employed toindicate on- Elate 4 the angle. ofthe hi or valley of t e rooflto be measured.` anithe rule 6 may be positioned atany'l degree with respect to the. plate 4 and rule 1.. \In Figure 1 I have shown my novel instruhave. it understood that the various rules are readily adapted for immediate disengagement' from each other for the purpose of storage.

Y The rule 9 of my device as shown is pro-` vided with markings and is further pro- Vlded With a plate 7 havin downwardlydependlng tongues 8 throng the medium of which the rule 1 may be readily moved into such a position with respect to the ton ues 8 so as to be engaged thereby and retained 1n proper relative positionwith respect to the rule 9.

The short rule 10 is fulcrumed by means of a pin to the plate 7, and said rule is further provided wlth a lower extension 11 having the side portions 1 2, that areadapted to engage the. plate7 of the rule 9. The rule 10 is provided with an upper portion having the linger portion 14 and the bod of the upper end of the rule 10 is adapte to par.- tially surround the rule 9 as shown in Figure 3. 85

The rule 1 O.has`al so been provided with the graduations- 13 as shown. It will lbe apparent that the rule 10 may be swung away from the rule 9, by simply exerting pressure on the plate 11, and the said rule may in turn be moved to snugly rest against the rule 9, by pressing against the portion 14 of said rule 10 and pushing said rule 10 against the rule 9.

In order to enable those skilled in the art to appreciate the workingof my invention, I am 'ving herewith two examples of the operation of the device. We will suppose for example that a building is 24 wide and the roof 'thereof 5 high. It can be easily 10U determined that the distance from the end of the buildin to the first main rafter should` be one-hal the width of the building or twelve feet. Of course it is presumed that the roof is provided with a hip and in using 105 my novel instrument to determine the length ofj the hip rafter, the scale of 1 for 1 on my instrument is employed. In measuring this roof to determine the length of the hip rafter I merely stop the leg 9 at the gradua- 110 tions 12 on the le 1 and then I line up the member 10 with tie leg 9 and cross the leg 6 at 5 on the member 10 and thenthrowthe member 10 out of position on the leg 9 and it will be seenthat the length of the main rafter will be 13' and that the leo' 6 will indicate the length of uw nip reiter. which is 17 81/2.

The graduations on the member 10 are provided in order to enable the operator to determine the incline he is working to. This incline is determined by merely crossing the leg 6 on any desired number on the member- 10. If the leg 6 is crossed, for exam le, at the graduation on member 10, the ra ter will run at an incline oi 5 on 13 as disclosed by my novel instrument. vThe number 5 on the member is always coincident with 13 on member 9 and the angle of the roof or reiter is determined by the position the slide 7 is stopped on the barv 1. For instance, if the slide '7 is stopped on the bar l at 20 the angular position of the member 6 with respect tothe member 10 if the member 6 is stop ed'at 5 will naturally be more severe than if the slide 7 is moved to the right to the oint and the member 6 is crossed on tie member l0 at 5. In the latter case the angle of the bar 6 will not be as severe as in the first instance.

These graduations on the member 10 are obtained for a structure 24: in width by taking all main rafter lengths up to l5 degrees. By considering the followinr example the use of the protractor 4 and the graduations on the member 9 that are not included between 1 to 12 inclusive on member 10will be understood. For example, 13 on the leg 9 is the main ra-ter length for a structure 24 in width with a rooi5 5 high. Graduations 5 to the left of 45 degrees on protractor 4 point off 671/2 degrees which is the incline of said-rafter-in-the roof. In order to explain the use of thegraduations on member 9 that arenot'included 'from 1 to 12 on themember 10, I would state that O on member 10 is directly over 12 on leg 9; 5 on the member 10 is directly over 13 on leg 9; so therefore 12 is the center of a structure 24 in width and where the roof is 5- high on' a strpgture, the length of the main rafterv 1s Graduations 2 to 12 on leg 9 are used-as'y follows:

Cross leg 6 at 5 on member 10 and then more leg 9 back half way to the screw 5, le 6v will then be across leg 9 at 61/2 which ist e main rafter length for a structure 12 in width having a roof 2 6 high. Graduations 2 to 12 are also used forsteeple meas-` uring. For a tower 10 square with a roof 12 high, number 5 on leg 9 would 'be'the center, while 5 on member 10 is over 13 on. leg 9 which is the rafter length. `Numberl 54 above degrees on protractor 4 will 'be op-iposite 671,/2 degrees, which is the incline of the roof. The incline of the roof is given by corresponding figures on member 10 and outer graduations on protractor 4 and to illustrate ,we would take a roof with a 12 foot run and foot rise. would know to look below 45 degrees t0 read the given incline; five run and twelve rise' lthe operator'would look above 45 degrees t0 read the incline. Manifestly 5 below is op-4 posite number 221/2 while A5 above 'isjopposite 671/2 degrees, the total being 90. The eg 6- across member 10 will be over the degree that indicates the degree of angle of the hip rafter with resplect to themam rafter and does not give t e degreesv of the incline of the roof. r

Graduations 17 to'30 on leg 9 follows: y

Stop leg 9 at 12 on leg 1 and cross leg 6 at 5 on member 1Q then move'leg 9 along the leg 1 at 18. The leg 6 will be across e at 191/2 which is the main rafter length a structure 36 in Width and 7 6 high.

Member 10 starts at 12 on leg 9 and the term 5 on member 10 means that 5 is the height per foot on the main rafter, so where the structure is 28' in width, the roof would be 14 times 5 in height, which equals 5 10 Graduation 5 on member 10 is obtained as follows, by the angle across the square from are used as 12 on one given line to 5 on the opposinggiven line, and likewise the scale on member 10 is obtained. After the calibration of member 10 'is completed, I place' le'g 1 at.

right angles to leg 9 and member 10 so that leg 6 'would` measure thefhip by crossing member 10. I use 5 for an exampley as it 1sA the easiest to explain, but Ithe entire scaleis used likewise. The leg 9 is used to measure from the eide plate of the roof to the center thereof and.

to measure themain rafter and is the only element in my ing.

from the corner of a structure to the first main rater; said measurement equals half,

the width of the structure on a four hip roof. The various graduatons on. the 'member 9 are provided in order to accomplish meas,

ent is I n fIn a measurmg mstrument, thc combina-- tion of a platehaving graduations marked thereon, a horizontal rule having gradua' tions thereon and secured permanently at o'ne side of the plate, arule for determining angles; in conjunction with the horizontal: rule., means for pivotally securing the said.

rule '.tofth'e' plate, a vertical rule having device that does such measur-` Leg 1 is usedto measure the differencel described my invention, what I.

The operator les whereb t e verticalrule may be moved 5 along t 1e horizontal rule, and a fourth rule pivotally rule and oined to the base of the vertical avlng graduations on its upper end and further bein provided with an upper portion that is a apted to partially sur round a portion of the vertical rule.

In testimony whereof I have hereunto set my hand'.

ELISHA AT'TAWAY. 

